Variable alarm control device

ABSTRACT

A VARIABLE OR ADJUSTABLE CODE WHEEL FOR A BACK-UP ALARM OF THE TYPE THAT HAS A PAIR OF ELECTRICAL CONTACTS AND AN ACTUATOR ARM OPERATIVELY ASSOCIATED WITH THE CONTACTS AND IN BEARING CONTACT WITH THE PERIPHERY OF THE CODE WHEEL. THE CODE WHEEL IS FORMED OF TWO DISKS THAT CAN BE ROTATED RELATIVE ONE ANOTHER TO VARY THE COMPOSITE PERIPHERY OF THE CODE WHEEL. VARIATION OF THE COMPOSITED PERIPHERY OF THE CODE WHEEL EFFECTS VARIATION OF THE SOUND PATTERN PRODUCED BY THE BACK-UP ALARM.

Feb. 9, 1971 RASCHKE 3,562,738

VARIABLE ALARM CONTROL DEVICE Filed July 24, 1968 62 e4 66 so eoLJ LFes Us? 44 e0 84 as as so U82 LU Use 34 f g. 6b.

HE RBER T A. 'RASCHKE 3 4 v INVENTOR.

Fig 7b loumsend %flownsend United States Patent Office 3,562,738 Patented Feb. 9, 1971 3,562,738 VARIABLE ALARM CONTROL DEVICE Herbert A. Raschke, Greenbrae, Califi, assignor to E. D. Bullard Company, Sausalito, Calif. Filed July 24, 1968, Ser. No. 747,248 Int. Cl. G08b 3/00 U.S. Cl. 340-329 4 Claims ABSTRACT OF THE DISCLOSURE A variable or adjustable code wheel for a back-up alarm of the type that has a pair of electrical contacts and an actuator arm operativcly associated with the contacts and in bearing contact with the periphery of the code wheel. The code wheel is formed of two disks that can be rotated relative one another to vary the composite periphery of the code wheel. Variation of the composited periphery of the code wheel effects variation of the sound pattern produced by the back-up alarm.

This invention relates to a variable cam or code wheel for controlling an electro-acoustic alarm sounder. For illustrating the invention, the structure is described hereinafter in connection with a vehicle back-up warning device of the type described in U.S. Pat. No. 3,380,022, which issued on Apr. 23, 1968.

The warning device described in the above-cited patent includes an electric motor that is energized when the vehicle on which it is mounted is backed up. Mounted on the shaft of the motor is a code wheel that has an irregular periphery; adjacent the code wheel is a switch that has an actuator for bearing on the periphery of the code wheel. The periphery of the code wheel has portions with a relatively large radius and portions with a relatively small radius. Only when the switch actuator bears against the large radius portion of the code wheel do the switch contacts close. The switch contacts are connected to an electric horn or like electro-responsive sound producing device so that a sound pattern corresponding to the peripheral shape of the code wheel is produced as the code wheel rotates. According to the present invention the peripheral configuration of the code wheel can be varied so as to provide for varying sound patterns.

In the above-cited patent there are disclosed code wheels of different peripheral shapes. These code wheels are interchangeable on a motor shaft to permit selection of different sound patterns. In accordance with the present invention, a code wheel having a variable peripheral shape is provided; when a different sound pattern is desired, the peripheral configuration of the code wheel is manually varied. Thus plural sound patterns can be produced with a single code 'wheel made according to the present invention.

An advantage of the present invention can be appreciated by considering an environment in which two or more vehicles are operated simultaneously. Provision of a unique back-up signal for each vehicle permits those working afoot in the environment to identify aurally each individual vehicle. Because the code wheel of the present invention is variable, plural sound patterns from a single code wheel are possible and such variability is achieved without the necessity for maintaining an inventory of replacement of code Wheels.

A corollary to the above-described advantage is that the code wheel of the present invention permits convenient variation of the alarm sound pattern without special tools. Variation of the sound pattern from time to time is desirable so as to avoid acclimation to the sound by those working in the environment.

The foregoing, together with other objects, features and advantages of the present invention, will be more apparent after referring to the following specification and accompanying drawing in which:

FIG. 1 is a perspective view of a variable code wheel embodying the present invention;

FIG. 2 is a cross-sectional view at enlarged scale taken along line 22 of FIG. 1;

FIG. 3a is a front View of the code wheel of the present invention with the two component disks thereof shown in registry with one another;

FIG. 3b is a graph of time versus position of the electrical contacts of a switch cooperating with the invention when in the position shown in FIG. 3a;

FIG. 4a is a view similar to FIG. 3a showing the component disks in a different position;

FIG. 4b is a graph similar to the graph of FIG. 3b and corresponding to the apparatus when in the position shown in FIG. 4a;

FIG. 5a is a view similar to FIG. 3a showing the component disks at a still different position;

FIG. 5b is a graph similar to the graph of FIG. 3b and corresponding to the apparatus when in position shown in FIG. 5a;

FIG. 6a is a view similar to FIG. 3a showing the component disks in another position;

FIG. 6b is a graph similar to the graph of FIG. 3b and corresponding to the apparatus when in the position shown in FIG. 6a;

FIG. 7a is a view similar to FIG. 3a showing the component disks in yet another position; and

FIG. 7b is a graph similar to the graph of FIG. 3b and corresponding to the apparatus when in the position shown in FIG. 7a.

Referring more particularly to the drawings, a component disk 12 and a substantially similar component disk 14 are held in coaxial face-to-face relationship by a hub 16. Hub 16 includes a shoulder 18 against which disk 14 bears. Spaced from shoulder 18 axially of hub 16 by a distance slightly in excess of the combined thickness of component disks 12 and 14 is a groove 19 for receiving a retaining ring 20. Between retaining ring 20 and disk 12 is a spring washer 21 that urges the confronting faces of the component disks 12 and 14 into frictional engagement with one another so as to resist, but not prevent, relative rotational movement between the two component disks. Hub 16 is centrally bored at 22 so as to adapt the device for mounting on a driven shaft, a set screw 23 being provided to fix the device to the shaft.

Disk 12 has around the periphery thereof a first plurality of segments of a relatively small radius and a second plurality of segments of a relatively large radius. In the drawings, the segments of small radius are desig nated 24, 26 and 28, and the segments of large radius are designated 30, 32 and =34. Disk 14 is identical to disk 12 and has similar portions that bear the same reference numerals that are primed. This is to say, disk 14 includes small radius portions 24', 26' and 28', and large radius portions 30', 32' and =34. Because the disks 12 and 14 are rotatably movable with respect to one another, the composite peripheral configuration of the disks is variable.

For establishing preselected relative positions of the disks, disk 12 is provided with an index hole 40. Disk 14 is provided with plural indicator holes that are radially spaced from hub 16 by an amount equal to the radial spacing of index hole 40. In the embodiment shown in the drawing, the holes in disk 14 are designated 43, 44, 45, 46 and 47. In FIG. 3a indicator hole 43 is aligned with index hole 40, and in that position the two disks are in registry with one another so that the composite peripheral configuration is the same as the peripheral configuration of either of the individual disks. A screw S can be installed through holes to assure retention of the relative position between disks 12 and 14. Shown in FIG. 3a is a switch that has an actuator arm 52 bearing against the composite periphery of disks 12 and 14. When actuator arm 52 is moved toward the main body of switch 50, normally open contacts typically included in such switch will be closed. When actuator arm 52 is permitted to move away from the main switch body such contacts will assume their normal open position. Thus, assuming that the disks are rotated at a constant speed, the time sequence of switch actuation will correspond to the composite peripheral configuration formed by the disks.

If it is considered that the structure is rotatably driven in a clockwise direction as viewed in FIG. 3a by mechanism of the type described in the above-cited patent, the contacts of switch 50 will open when the relatively small radius segment 28 is opposite the switch actuator. Such condition of the contacts is indicated at 54 in FIG. 3b. After the disk has rotated to a position at which relatively large radius segment 32 is opposite the switch actuator, the switch contacts will be closed, a condition indicated at 55 in FIG. 3b. The contacts will stay closed until the relatively small radius segment 26 moves to a position opposite the switch actuator arm 52, at which time the contacts open. The open condition of the contacts is indicated at 56 in FIG. 3b. In turn segment 30 closes the contacts (indicated at 57 in FIG. 3b), segment 24 opens the contacts (indicated at 58 in FIG. 3b), and segment 34 closes the contacts (indicated at 59 in FIG. 3b). An electrical load such as an electro-responsive sounder 51 is connected in series with a power source 53 and the contacts of switch 50, so that sounder 51 will be actuated and de-actuated in accordance with the above-described time pattern.

FIG. 4a shows the relative position of the disks 12 and 14 when indicator hole 44 of disk 14 is moved into registry with index hole 40 in disk 12. Commencing again at the 3 oclock position and considering that the disks are driven in a clockwise direction, the switch contacts are sustained in a closed position by segment 34', such closed position being indicated a"; 60 in FIG. 411. When segment 28 rotates to a position opposite the switch actuator, the switch contacts are permitted to open as indicated at 62 in FIG. 4b. After further rotation, segment 32 closes the switch contacts (indicated at 64 in FIG. 4b), and then the contacts are opened when small radius segment 26 moves opposite the switch (indicated at 65 in FIG. 4b) thereafter, segment 32 closes the switch contact (indicated at 66 in FIG. 4b) until segment 26 moves opposite the switch and permits the contacts to open (indicated at 67 in FIG. 4b). Finally, segment 34 moves opposite the switch actuator to complete one cycle of rotation and begin a succeeding cycle. The signal pattern produced by the device when positioned as shown in FIG. 4a is characterized by one long signal and two short signals with relatively short silent periods between signals.

The disks 12 and 14 are moved to the relative position depicted in FIG. 5a by aligning indicator hole 45 in disk 14 with index hole 40 in disk 12. Beginning the description of the structure of 5a at the 3 oclock position, it will be seen that for the first few degrees of clockwise rotation the contacts will be open because actuator 52 bears against segment 28 of disk 12 and segment 24' of disk 14. The condition of the contacts is indicated at 70 in FIG. 5b. Thereafter the contacts are closed when segment 34' of disk 14 and segment 32 of disk 12 move opposite the switch actuator, a condition indicated at 72 in FIG. 5b. The contacts open when segment .26 moves opposite the switch actuator (indicated at 74 in FIG. 5b); then the contacts close as segments 30, 32' and 34 move opposite the actuator (indicated at 76 in FIG. 5b).

Indicator hole 46 in disk 14 is moved into registry with index hole 40 in disk 12 to position the disks as shown in FIG. 6a. At the 3 oclock position, segment 20 retains the contacts in a closed position as indicated at 80 in FIG. 6b. Rotation of the device in a clockwise direction brings segment 28 opposite the switch actuator 52 so as to open the contacts as indicated at 82 in FIG. 6b. Thereafter, the contacts are again closed by segment 34' and segment 32, a condition indicated at 84 in FIG. 6b. In turn the contacts are opened by segment 26 (indicated by 86 in FIG. 6b), closed by segment 30 (88 in FIG. 6b), opened by segment 24 (89 in FIG. 6b), and closed by segments 34 and 30" (80 in FIG. 6b).

The final relative position of disks 12 and 14 in the embodiment shown in the drawings is depicted in FIG. 7a and is achieved by positioning indicator hole 47 in registry with index hole 40. As the code wheel rotates clockwise with respect to the 3 oclock position, the contacts of switch 50 will be opened when segment 28 is opposite the switch actuator. Such is indicated at 90 in FIG. 7a. In succession, segment 30 closes the contacts (92 in FIG. 7b), segments 28 and .24 open the contacts (94 in FIG. 7b), segments 32, 34' and 30 close the contacts (96 in FIG. 7a), segment 24 opens the contacts (98 in FIG. 7b), and segment 34 closes the contacts (99 in FIG. 7b).

The specific peripheral configurations disks 12 and 14 are shown only by way of example, since other configurations are considered within the scope of the present invention. Additionally, the number and location of indicator holes is not to be taken as limiting since other numbers and positions of holes are within the scope of the invention. Although one embodiment of the invention has been shown and described, it will be obvious that H other adaptations and modifications can be made Without departingfrom the true spirit and scope of the invention.

What is claimed is:

1. In a signaling device of the type having an electroresponsive sounder, a power source for energizing the sounder, a switch connected in series between the power source and the sounder, such switch including an actuating arm and electrical contacts operatively associated with said arm, and means for actuating said arm to alternately open and close said contacts in timed sequences; the improvement comprising first and second disks each of which has a periphery formed With at least one first segment having a relatively large radius and at least one second segment having a small radius, means for securing said disks to one another in coaxial relationship to form a composite generally circular body that has a peripheral configuration having alternate large radius and small radius portions, said securing means including a resilient element that compresses said disks toward one another so that faces of said disks are in frictional contact with one another so as to create a force that resists relative rotative movement of said disks, said securing means being arranged so that the friction force can be manually overridden to permit relative rotation of said disks to vary the peripheral configuration of said composite body, and means for drivably rotating said disks at a position adjacent said switch actuator so that said contacts are open when the actuator rests on a small radius segment of said composite body and so that said contacts are closed when the actuator rests on a large radius portion of said composite body.

2. The invention of claim 1 wherein both said disks are centrally apertured and wherein said securing means comprises a hub having a shaft portion extending through said apertures, an enlarged shoulder portion at one end of the shaft portion, and a groove at the other end, a spring washer having a concave surface facing said disks and being centrally apertured to fit over said shaft p tion, and a retaining ring disposed in said groove to retain the parts in operative assembly on said shaft portion 5 so that the spring washer is stressed to compress said disks together.

3. The invention of claim 1 wherein one of said disks has an index hole spaced radially from the center thereof and wherein the other of said disks has a plurality of indicator holes therein that are circumferentially spaced from one another and are uniformly radially spaced from the center by an amount equal to the spacing of said index hole so that the indicator holes can be individually moved into registry with said index hole to establish different relative rotative positions between said disks.

4. The invention of claim 1 wherein said disks have circumferential extent of individual said first segments UNITED STATES PATENTS 9/1928 Hcbern 340357 4/1932 Tibbetts 340329 10 THOMAS B. HABECKER, Primary Examiner US. Cl. X.R. 34070, 357 

